a11y: address PR feedback and polish docs

- HistoryTable: skip row key handler when focus is on Actions button (Enter/Space)
- StoryList: expose selected story (aria-pressed, 'Selected' in label)
- ProfileCard: skip card key handler when focus is on Export/Edit/Delete
- VoicesTab: keep table semantics; edit button in first cell instead of role=button on row
- PR-ACCESSIBILITY.md: 'Fine-tune' wording, 'focus on the text area' phrasing

Made-with: Cursor

app/src/components/VoiceProfiles/ProfileCard.tsx

@@ -62,6 +62,8 @@ export function ProfileCard({ profile }: ProfileCardProps) {
   };
 
   const handleKeyDown = (e: React.KeyboardEvent) => {
+    const target = e.target as HTMLElement;
+    if (target.closest('button')) return;
     if (e.key === 'Enter' || e.key === ' ') {
       e.preventDefault();
       handleSelect();